presentation eng0 [modo de compatibilidade] - ecreee · august 25, 2011 day four 25 august 2011...
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August 25, 2011Day Four 25 August 2011
RETScreen Training on RE&EE Project Analysis by ECREEELocation: KNUST, Kumasi, Ghana
Time Session09:00 1 RETs_2: Wind Energy Technology: Power point presentation - Energy
Project Analysis and demonstration of calculation of case studies on Wind
power generation
10:30 Tea/coffee/cocoa break
11:00 2 Case Studies: Group work – Discussion of group work - comments
12:45 Lunch break
14:00 3 RET_3: Mini-Hydro Power Generation
-Power point presentation – example of case study
-Case study: Hydro power generation – Group discussions - Project
Analysis of case studies from the ECOWAS region to be undertaken by the
participants in working groups – Presentation of calculations of case
studies by working groups and discussions
15:30 Tea/coffee/cocoa break
16:00 4 RET_4: Thermal Energy Analysis
Power point presentation – Solar Thermal heat – Case study –Group
discussions
RET_5: Biomass based combined heat and electricity generation
18:30 End of Day Four
5. Wind Energy Project Analysis
5.1 Objective
Present wind energy projects analysis using RETScreen
• Electricity for
– Central-grids
– Isolated-grids
– Remote power supplies
– Water pumping
…but also…
What do wind energy systems provide?
San Gorgino Windfarm, Palm Springs, California, USA
…but also…
– Support for weak grids
– Reduced exposure to energy price volatility
– Reduced transmission and distribution losses
Photo Credit: Warren Gretz/ NREL Pix
Wind Turbine Description
• Components
– Rotor
– Gearbox
– Tower
– Foundation
– Controls
Schematic of a Horizontal Axis Wind Turbine
– Controls
– Generator
• Types
– Horizontal axis
• Most common
• Controls or design turn rotor into wind
– Vertical axis
• Less common
Utilisation of Wind Energy
• Off-Grid
– Small turbines (50 W to 10 kW)
– Battery charging
– Water pumping
• Isolated-Grid
– Turbines typically 10 to 200 kW
Off-Grid, 10-kW Turbine, Mexico
– Turbines typically 10 to 200 kW
– Reduce generation costs in remote areas: wind-diesel hybrid system
– High or low penetration
• Central-Grid
– Turbines typically 200 kW to 2 MW
– Windfarms of multiple turbines
Photo Credit: Charles Newcomber/ NREL Pix
5.4 Classification des réseaux éoliens
• Hors réseau
– Petites éoliennes (50 W à 10 kW)
– Chargement de batteries
– Pompage de l’eau
• Réseau isolé
Hors réseau, éolienne de 10 kW, Mexique
– Éoliennes de 10 à 200 kW
– Les systèmes hybrides éolien-diesel réduisent les coûts de production dans les régions éloignées
– Taux de pénétration élevé ou bas
• Réseau central
– Éoliennes de 200 kW à 2 MW
– Parcs éoliens de plusieurs machinesPhoto : Charles Newcomber/ NREL Pix
• High average wind speeds are essential– 4 m/s annual average is minimum
– People tend to overestimate the wind
– Wind speed tends to increase with height
• Good resource
Wind Resource
– Coastal areas
– Crests of long slopes
– Passes
– Open terrain
– Valleys that channel winds
• Typically windier in– Winter than summer
– Day than night
1 MW Turbine Power Curve
0
200
400
600
800
1,000
1,200
0 2 4 6 8 10 12 14 16 18 20 22 24Wind speed (m/s)
Pow
er (
kW)
Examples: Europe and USACentral-Grid Wind Energy Systems
• Intermittent generation not a problem: 17% of Denmark’s electricity is from wind with no additional reserve generation
• Quick projects (2 to 4 years) that can grow to meet demand
Coastal Windfarm, Denmark
Photo Credit: Warren Gretz/ NREL Pix
Windfarm in Palm Springs, California, USA
• Land can be used for other purposes, such as agriculture
• Individuals, businesses, and co-operatives sometimes own and operate single turbines
Photo Credit: Danmarks Tekniske Universitet
RETScreen®
Wind Energy Calculation
See e-Textbook
Clean Energy Project Analysis: RETScreen® Engineering and Cases
Wind Energy Project Analysis Chapter
Conclusions• Wind turbines provide electricity on and off grid world-
wide
• A good wind resource is an important factor for successful projects
• Availability of production credits or Greenpower rates are important for on-grid projects
• RETScreen® calculates energy production using annual data with an accuracy comparable to hourly simulations
• RETScreen® can provide significant preliminary feasibility study cost savings
Next: Energie Eolienne, quelques cas d’etudes pratiques
6. Small Hydro Project Analysis
Run-of-River Small Hydro Project, Canada
© Minister of Natural Resources Canada 2001 – 2004.
Photo Credit: SNC-Lavalin
Objectives
• Review basics of Small Hydro systems
• Illustrate key considerations for• Illustrate key considerations forSmall Hydro project analysis
• Introduce RETScreen® Small Hydro Project Model
© Minister of Natural Resources Canada 2001 – 2004.
• Electricity for
– Central-grids
– Isolated-grids
– Remote power supplies
…but also…
What do small hydro systems provide?
…but also…
– Reliability
– Very low operating costs
– Reduced exposure to energy price volatility
Photo Credit: Robin Hughes/ PNS
© Minister of Natural Resources Canada 2001 – 2004.
Small Hydro System Description
Head (m)Head (m)
Flow (m3/s)
Power in kW ≈ 7 x Head x Flow
© Minister of Natural Resources Canada 2001 – 2004.
World Hydro Resource
• More rain falls on continents than evaporates from them
• For equilibrium, rain must flow to the oceans in rivers
Technical Potential
(TWh/year)
% Developed
Africa 1,150 3
South Asia and Middle East 2,280 8
China 1,920 6
Former Soviet Union 3,830 6
North America 970 55
South America 3,190 11
Central America 350 9
Europe 1,070 45
Australasia 200 19
© Minister of Natural Resources Canada 2001 – 2004.
Source: Renewable Energy: Sources for Fuels and Electricity, 1993, Island Press.
• “Small” is not universally defined
– Size of project related not just to electrical capacity but also to whether low or high head
“Small” Hydro Projects
capacity but also to whether low or high headTypical
Power
RETScreen®
Flow
RETScreen®
Runner Diameter
Micro < 100 kW < 0.4 m3/s < 0.3 m
Mini 100 to 1,000 kW 0.4 to 12.8 m3/s 0.3 to 0.8 m
Small 1 to 50 MW > 12.8 m3/s > 0.8 m
© Minister of Natural Resources Canada 2001 – 2004.
Site Hydro Resource
•• Very site specific: an exploitable river is needed!Very site specific: an exploitable river is needed!
� Change in elevation over a relatively short distance (head)
� Acceptable variation in flow rate over time: flow duration curve
� Residual flow reduces flow available for power
Flow-Duration Curve
0.0
10.0
20.0
30.0
40.0
50.0
0 10 20 30 40 50 60 70 80 90 100Percent Time Flow Equalled or Exceeded (%)
Flo
w (m
³/s)
•• Estimate flow duration Estimate flow duration curve based oncurve based on
� Measurements of flow over time
� Size of drainage above site, specific run-off, and shape of flow duration curve
© Minister of Natural Resources Canada 2001 – 2004.
Example Validation of the
RETScreen®
Small Hydro Project Model
• Turbine efficiency
– Compared with manufacturer’s data for an installed 7 MW GEC Alsthom Francis turbine
• Plant capacity & output
– Compared with HydrA 20%
40%
60%
80%
100%
Effi
cien
cy (
%)
Turbine Efficiency Curves: RETScreen vs. Manufacturer
RETScreenManufacturer
– Compared with HydrA for a Scottish site
– All results within 6.5%
•• Formula costing methodFormula costing method
� Compared with RETScreen®, within 11% of a detailed cost estimate for a6 MW project in Newfoundland
0%0% 20% 40% 60% 80% 100%
Percent of Rated Flow
RETScreen vs. Manufacturer
© Minister of Natural Resources Canada 2001 – 2004.
Conclusions
• Small hydro projects (up to 50 MW) can provide electricity for central or isolated-grids and for remote power supplies
• Run-of-river projects:
– Lower cost & lower environmental impacts
– But need back-up power on isolated grid– But need back-up power on isolated grid
• Initial costs high and 75% site specific
• RETScreen® estimates capacity, firm capacity, output and costs based on site characteristics such as flow-duration curve and head
• RETScreen® can provide significant preliminary feasibility study cost savings
© Minister of Natural Resources Canada 2001 – 2004.
Next: Energie Hydroelectrique quelques cas d’etudes pratiques
RETScreen Version 5
• Energy audit analysis
Soleil, source des energies